Pressure surge controlling means



Sept. 22, 1936. R. BISCHCFF 2,055,193

PRESSURE SURGE CONTROLLING MEANS Filed Ju1y 26, 1954 FLOW BLOWER OR PUMP INVENTOR ROBERT BSCHOFF ATTORNEY Patented Sept. 22, 1936 ATEN T o FFIC-E' PRESSURE SURGE ooN'rRoLtmG MEANS Robert Bischoff, York, Pa., assignor to S. Morgan 7 Smith Company, York, Par, a'corporation of:

Pennsylvania imam .niiy' 26, issigseri i 1a. 136,999

1 Claim. (01. 230-115) The present invention relates to means for controlling surges in fluidconveyingpipe lines, and isespecially adapted foruse withfluid systems including fluid propelling mechanism, a conduit leading from the fluidpropelling mechanism, and a valve device, for controllinguthef flow of fluid through the conduit.

f In fluidsystems including propelling mechanisms suchras blowers or pumps, and the like, it has beenvthe practice to install in the conduits leading from the pressure side of the fluid propelling mechanisms, valve. devices or similar means ,for controlling the. flow of fluid through the conduits. Generally speaking, these .valve devices function as'check valves, so that when the fluid propelling mechanisms are stopped, the valve devices will automatically close the conduits and prevent back pressure of the fluid from reaching the fluid propelling mechanisms. This is necessary, because it is well known that upon the stopping of a fluid propelling mechanism it isnecessary to have some means for "preventing a reverse flow of the fluid, as such reverse flow of the fluid causes thev fluid propelling mechanism to reverseits rotation, with resultant damage to the bearings and other parts thereof.v v

Heretofore, it. has been proposed to employia quick acting type of checkvalve forcontrolling the flow of fluid delivered by'afluid'propelling mechanism to a pipe line or conduit. "I'hese check valveshave been mostly of the swing or disccheck types, having either single or multiple ports.

. In actual-practice ,the disc. type of check valve, when ,used for theabove mentioned purpose, has been found to have certain disadvantages, in that, l(1) there is a very appreciable loss of pressure .through this type of check; (2) the disc type check valve is notvery tight, thereby making it necessary to,,also-install,a shut-off valveinthe conduit; ,and, (3)v the disc type check valve is not positive, the opening of the valve depending upon the ,creation of flow' through the valve and the closing of the valve depending upon the cessation of suchflow. r. 7 j f Furthermore disc type check valves require periodical attention and overhauling. If this is notattended to, at regular intervals thevvalves will not close properly when, the fluid propelling mechanism is shut down, thereby permitting the ,-fluid to flow back to the fluid propelling mechanism and cause the same to reverse itsrotation, ,with resultant damage thereto. v a

In orderto. provide means for. obviating all the above adverse conditions, ithas been proposed to substitute an automatically operable plug valve for the quick acting type of check valve heretofore installed in the conduit on thepressure side ofa fluid'propelling mechanism, Byemploying a plug valve therel is no loss of pressure because, first, with the plug in open position, there is a straight, open passage, equal in areato a pipe of the same length; second, a plug valve istig'ht when closed and thereforean additional shut-01f valve is not required; and, third, the automatically operable plug valve is'positive in action, because it is pressure operated and it does not require periodical overhaulingg vHowever, in fluid systemsof the above type having an automatically operable plug valve for c'ontrolling'the flow of fluid from the fluid propelling mechanism, when the fluid propelling mechanism is first started the plug valve is not sufliciently sensitive in operation to check surges and pulsations in the conduit and thereby enable the fluidpropelling mechanism to quickly take on load and attain its proper speed for delivering fluid atethe desired pressure to the conduit.

.An object of the present invention is to provide nansforby-passing fluid from the pressure side of a fluid propelling'mechanism so as to suppress surges and pulsations in the conduit on the pressure side ofthe fluid propelling mechanism while the fluid propelling mechanism is taking on load, prior to the operation of the main control valve to wide open position. j J g H 3 Anotherobject oftheinvention is to provide means for bypassing fluid from the pressure side ota fluid pressure system of the above type 'so that the surges are damped out almost immediately.,- a

Another object of the invention is to provide means for by-passing fluid from the conduit on the pressure side oia fluid pressure systemof the above type so that a predetermined amount of fluid is, by-passed around the main control valve before the main control valve on the dischargeside [of the fluid propelling mechanism is opened.

Another object of the invention is to provide an improved means for controlling the flow of fluid through a fluid pressure system of thecharacter mentioned, which is simple in construction, and

more-fully described and claimed.

In the accompanying drawing the single figure 3+ d g ammaticfview,

and combination of theseveral parts of, which it iscomposed, as will be hereinafter partly in section' of a fluid pressure system embodying the present invention.

Referring to the drawing, the apparatus may comprise a blower or pump I I of any desired type, from the pressure side of which there leads a pipe, main, or conduit I2. The blower or pump II may be used for forcing fluids, such as air, gases, etc, or quidsgsuch as water, etc:, through the conduit I Mounted in the conduit I2 and adapted to control the fluid delivered thereto by the blower' or pump I I, is a valve device I3, also of any approved type. If so desired'valve I3 may be of the automatically operatingqtype.

The valve l3 has a cavity :I 5 formed therein. for a plug I6. The cavity I5 is intersected by a longitudinal water wayor opening. Which ,consti.--

tutes passages II, I8 throughthe valve, the pas-' sage I'I being on one side of the cavity IS and. the. passages I8 ,beii 1g v on the, other. side of. said cavity, v'I'hel Plug; Ibl'has, a passage j l9'1formed therein; Thegpassagesill, Wen ie areOf the samediameter, so thatQwhen the plug. I'Bis in the open position, aluniform ,bore wi1l" extend through the valve fromend to. end; 7

Y According to thepresentinvention a,:by- -pass 20' connects theconduit. IZLonone. side of the valve 13 with the. conduit I2 on the other side of said thereby smaller than. the area ,of conduit- I2 ibut'sufilcient for the purpose, as willbe hereinafter described.

Communication through by-pass 20" is controlledby a check,.valve2.f piyotall'y mounted'as at 22,..andadapted' to, swing inthe direction of flowthroughthe by pass as indicated by the arrow in the. draizlzing,v in order to. .permit. fluid to floWaroundthemain control valve I3'as' willbe hereinafter. more 11113. described. No ma y check. valve 2|.- is..seated' aga;inst itsfseat. 23 and cuts offcommunication through b t-pass Also installed inthe by-pass .20, is a gate valve 2.5;, Obviously} any suitable, type'off valve device may, be, herefleniployed but in the. instant case, amanually operable type of gate valve is 'shpwm Howeversvalvedevices' ofiother forms may alsofibe. employed, when so desired. As shown,, valve. ZET-ha's, agate 2.Ii; the position of which is controlled by a hand; wheel or other operating. means. 2],. .Themai'nb'ody of the valve 25- isformed withajseat 2B for the gate 26 when [the latter. is in. closed, position. Normally, the

gate125- israised to .its wide open position as is shown in the drawing."

1 inoperation and assuming that the blower or 7 pump-I I .has beenfshut. down. and it is desired to startlthebloweror puinpfbr the purpose ofdelivering fluid .underypressure, to the conduit I 2,

.theplug. l6 .of, .automatically operable control valve. device L3. .willfbe. in. the closed-position shownin. the. drawing, in, which position'fluid in conduitsflfion. the .righthand side of'valve I3 is p zeyented .from'. flowing... back; to the blower or ma When the blower orrpump I I is. first .startedthe ,flund under. pressurein, conduit I2 on the blower side of closed control valvel3willflow into bypassill andopen check valve 2! which action pernits, the. fluid to. flow aroundcontrol' valve I 3 and ime conduit ,I2. entireopposite side thereof. Sincether communication through by-pass' 20 is controlled by a,'. ,c hecln valve 2 I i which automatieally opens upon anincreasein pressure and auto- ;maticalycloses upona drop in pressure, and since a surge consists of a series of pressurerises' and drops, the check valve 2| opens and closes until the surges resulting from the initial operation of the blower or pump II are smoothed out. In this way a predetermined quantity of fluid under pressure from blower or pump II is by-passed around 5 the closed main control valve I3.

After the blower or pump I I has taken on load sufiicfently so that' the pressure of the fluid delivered therefrom equals or overloalances the back pressure of the fluid in conduit I2, the main con- 10 trol valve device I3 is opened so that fluid under pressurefromtheblower or pump will be delivered through passages I'I, I9 and I8 to the conduit. I2.- ,Wherr th'e valve device I3 is fully opened,i the checInvEalve 2| in by-pass 20 seats 15 against its-seat '23; due to the balanced pressures -in .by,pa ss.2floniboth sides of valve 2|, thereby cutting off communication through by-pass 2Il.

By by-passing fluid from the pressure side of the blow.eror. pump ll around v alve device .l3 20 whiletheblowerorpump is taking on load; surges and. pulsationsiresulting. from fluid" flowing through valve .I 3jjwhile the}plug I6thereof ispartw 3'. open, lwililbe" dissipated @and not transmitted back to the ,blowerrorp ump; I e g It will also be understood thatanymeans' may beproyidediorautomatically actuating the main control Valved'eviceIB', since many types of valve devices suitable forthispurppseare readily pur i communication through the conduit is, cut oil by 40 the main, .control valve device I3. 7

After the pressureflof the fluid has been built up. the desiredamount andthe blo wenor pump is operating atfnorinal load, and. the main valve device I3'is open wide, the surges an'dpulsations whichset up vibrations in the apparatus when'the bloweror pump is attaining its rated; capacity, have disappeared; Duringthe normal operation ofjthe apparatus. the main vcontrplfvalve device I3 remains open, and upon the shutting down of'the apparatus, saidfvalve device is adapted to automatically'rclos'e and cutoff communication through the conduit fzf However, when it is desired'. to again start the blower'orpump', inorder to pre- 'ventthe. formation of surges and pulsations, it is necessary to first by-pass the fluid j from the blower orv pump around valve .13 in the manner heretofore described before the blower or pump has taken on load great enough toeffect the automatic operation of the valve 1 3 so. as to reestablish communication through the conduit I2.

Should it be necessary at any time to remove check valve ZI'for repairor'replacement, the gate ZBof valve. 25 can be moved to. its seat'28'thereby cutting ofi" communication through by-pa ss 20."

After check valve 2| has been again installed in the by-pass, the gate valve can be opened thereby permitting the check valve 2I' to control communication through by-pass 20;

Having. I claim is:

In a device of the class described, the combination with a centrifugal fluid propelling mechanism and, a conduit leading from the pressure side of said mechanism, o fln'eans for permittingsaid thusdescribed my invention, what "-T0 centrifugal fluid propelling mechanism to take on load and attain a normal operating speed from an inactive condition without producing surges of the fluid in the conduit, comprising a rotary plug valve for controlling communication through the conduit, the free fluid passage through the valve being of substantially the same diameter as the internal diameter of the conduit, and means for by-passing fluid from said centrifugal fluid propelling mechanism around the rotary plug valve when the plug of said valve is closed and said mechanism is taking on load and attaining the normal operating speed, comprising a passageway of smaller area than the area of said conduit, a check valve for controlling communication through said passageway, said check valve being operable only to permit the flow of fluid through the passageway in a direction to relieve the pressure of the fluid on the pressure side of said centrifugal fluid propelling mechanism when said rotary plug valve is closed, said plug valve being adapted to be opened when said mechanism has 10 taken on load.

ROBERT BISCHOFF. 

